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Flashcards in Tissues Deck (35)
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1

Epithelial tissues in general

Epithelial cell layer on surface (avascular)
Basal lamina (ECM) and a reticular lamina compose the basement membrane.
Connective tissue
Little ECM and often junctional specialization (tight junctions, desmosomes and gap junctions)
Frequent cell division because of exposure to exterior/lumen (called free surface)

2

Simple squamous

Thin = adapted for diffusion (gas, blood, waste, nutrients), filtration (urine in kidney glomeruli) and secretion (lubricating of lining body cavities)
Alveoli lungs, kidney glomeruli (bowman's capsule), lining heart, blood/lymphatic vessels.

3

Simple cuboidal

Secretion and absorption
Kidney tubules, small glands, ovary

4

Simple columnar

Ciliated= secretion/moving of mucus.
Small bronchi, uterine tubes, uterus.
Non-ciliated= contain microvilli = high absorption. Absorption and secretion in GI tract

5

Simple pseudostratified

Ciliated= Secretion and propulsion of mucus
Trachea, bronchi, respiratory tract.
Non-ciliated= Lining of male urethra

6

Stratified squamous

Thickest of all epithelia = protection
Keratinized= retains water, protects against friction and bacteria. Skin epidermis
Non-keratinized= Lining of wet surfaces like epiglottis, vestibule of mouth, tongue, esophagus, vagina

7

Stratified cuboidal

Protection
Largest ducts of sweat glands, mammary glands, salivary glands and urethra.

8

Stratified columnar

Protection and secretion
Very rare! Lines urethra, Large ducts of some glands and portion of conjunctiva of the eye

9

Stratified transitional

Lining of organs that stretch like bladder, ureters and urethra. Urinary organs

10

Stratified epithelium will be called accordingly

To the layer closest to free surface (lumen)

11

Glandular epithelium

Endocrine: No free surface, secrete Hormones into Blood, most of endocrine glands are epithelial derivatives formed by invagination and during embryo development they lose their ducts.
Exocrine: Release products onto free surface (skin or lumen) like GI, respiratory or reproductive tract.
1. Merocrine: no part of cell is lost (salivary)
2. Apocrine: top of cell is lost with secretion (mammary)
3. Holocrine: whole cell detaches with secretion (sebaceous)

12

Hypothalamus

Endocrine Master gland: Control center, controls anterior pituitary gland hormones

13

Anterior pituitary

Endocrine gland.
TSH: thyroid stimulating hormone: stimulate thyroid to produce Thyroxine (T4) and triiodothyronine (T3): brain development, metabolism, reproduction.
ACTH: adrenocorticotropic hormone: stimulates cortisol secretion from adrenal cortex
GH: growth hormone
FSH: follicle stimulating hormone and LH luteinizing hormone: act on gonads, growth of follicle, ovulation, stimulation of testosterone, fsh in male, androgen binding protein expression BREF sexual cell stimulation!
PRL: prolactin: milk synthesis from mammary glands
MSH: melanocyte stimulating hormone

14

Posterior pituitary

ADH/vasopressine: acts on kidney, water retention
Oxytocin- milk let down and uterine contraction during delivery

15

Smaller endocrine glands (other glands)

Pineal gland: produces melatonin, sleep
Thyroid gland: produces T3,T4, calcitonin. To decrease plasma, controls energy metabolism.
Adrenal cortex: mineralocorticoid like aldosterone (water retention), corticosteroids (increases bp and blood sugar and reduces immune responses, case of stress) and androgens for sex steroids
Adrenal medulla epinephrine and norepinephrine: stress adaptation
Pancreas: insulin, glucagon, somatostatin: nutrient utilization
Gonads: produces testosterone estrogen and progesterone.

16

General functions of connective tissues.

1. Support, binding. ex: Bone, cartilage, ligaments, tendons, connective tissue around other types of tissues.
2. Protection, defense, repair. Ex: Scar tissue, skull.
3. Insulation: fat cells (adipocytes).
4. Transportation. Blood cells.

17

ECM is made of

Ground substance: mineralized (bone), gelatinous(loose,dense, cartilage, adipose), watery (blood). Made of proteoglycans (polysaccharide groups on proteins allow to trap more or less water) and cell adhesion proteins (attach cells to ECM)
Protein fibers: fibronectin reticular (connect cells to ECM and support organs), fibrilin reticular (forms filaments and sheets to support organs), elastin (strech, yellow), collagen (stif but flexible, shiny white)

18

Fibroblasts

cells that secrete ECM in connective tissue proper

19

Chondroblasts

cells that secrete ECM in cartilage. 3 types of cartilage: hyaline (most common,looks like shiny eyes looking at us oo), elastic(elastic fibers), fibrocartilage(collagen fibers). Hyaline cartilage is repaired by fibrocartilage scar tissues.

20

Osteoblasts

cells that secrete ECM in bone

21

Hemocytoblasts

cells that secrete ECM in blood

22

Blood composition

Cells: RBCs (no nucleus), monocyte(neutrophils, moonshaped shadow), lymphocytes (type of WBCs, smaller), eosinophils (2 nuclei)
ECM: water

23

Loose connective tissue

Cells: fibroblasts.
ECM: more ground substance than fibers (collagen, elastic, reticular)
Skin, around blood vessels, organs, under eptithelia

24

Dense irregular connective tissue

Cells: fibroblasts
ECM: more fibers (random collagen) than ground substance
Muscle, nerve sheats

25

Dense regular connective tissue

Cells: fibroblasts
ECM: more fibers (parallel collagen) than ground substance
Tendons, ligaments

26

Adipose tissue

Cells: adipocytes (brown and white)
ECM: little ground substance and no fiber

27

Cartilage

Cells: chondroblasts
ECM: ground substance is hyaluronic acid (firm/flexible) and fibers are collagen

28

Bone

Cells: osteoblasts and osteocytes
ECM: ground substance is mineralized (calcium salts) and fibers are collagen

29

In general, ECM is made of

proteoglycans, fibrous proteins, glycosoaminoglycans

30

What is transcytosis

Transcytosis= endocytosis followed by exocytosis of the same substance.